The general objectives of this research are to define the pathways for formation and turnover of the major myelin phospholipid, the ethanolamine plasmalogens, to define the metabolism of myelin phosphoglycerides in relation to the phosphoglycerides of other membranes, and to characterize the phospholipases of white matter, particularly the plasmalogenase. Areas to be studied will include: 1) The synthesis of choline phosphoglycerides and ethanolamine phosphoglycerides by phosphotransferases. 2) The synthesis of choline and ethanolamine plasmalogens from the corresponding alkylacyl phosphoglycerides by plasmalogen synthetase. 3) The formation and turnover of glycerides in mouse brain after intracerebral injections of labelled glycerol and fatty alcohols. 4) The enzymes plasmalogenase and phospholipase L2 will be purified and characterized and the characteristics of phospholipases A1 and A2 will be determined in white matter and oligodendroglia.